Refiner for pulp, sawdust, and the like



Feb. 17. 1925. 1,526,461

H. G. CRAM HEFINER Fon PULP, sAwDUsT, AND THE LIKE Filed Feb. 15, 1921 '6 Sheets-Sheet 1 m vll/11111115 ZW/vena P: I

Feb., 17. *1925. H. G. CRAM REFINER Fon PULP, sAwDUsT, AND THE LIKE Filed geb.- 15, 1921` 3 Sheets-Sheet 2 Patented Feb. i7, i925.

HERVEY G. CRAM, O' NEIIPCIRT, `Ilf.f-i.`lfl`l'li"a, ASSGNOE GREAT NORTHERN :PAPER COMPANY, OF MILLINCKET, MNE, [1.

CORPORATIUN OE LAINE.

REFINER FOR PULP, SIDUET, AND THE LIKE.

Application filed February YTo all ui/10m t may concern:

i Be it known that I, l-lnnvnr (if. CRAM, a citizen of the United States, and a resident of Newport, county of Penobscot, and tritate of Maine, have invented an improvement in Refiners for Pulp, Sawdust, and the like, ,of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention relates to mechanisms for disintegrating material by grinding, and in particular to such a machine adapted for use in refining wood pulp or sawdust for use in paper making.

The invention will best be understood by reference to the following description of an illustrative embodiment thereof shown by Way of example in the accompanying drawings, wherein:

Fig. l is an elevation Vof an installation illustrative of my yinvention F ig. 2 is a central, vertical section through the hopper and feeding mechanism shown -in Fig. l;

`Fig. 3 is aV section on the line of F ig. l;

Fig.` 4 is a plan on a larger scale of the grinder proper with parts broken away to reveal the interior construction;

Fig. 5 is a longitudinal section of the same; and

Fig. 6 is a detail to be referred to viewed in end elevation.

Referring to Fig. l of the drawings, I have there shown a complete installation of the grinding mechanism adapted to be in* stalled in a mill and embodying a grinding or disintegrating machine proper T and in the present instance a mechanical feeding and pressure-applying mechanism 9 adapted to deliver pulp or the like to the grinder 7 through a lng passagewayT 1l.

I will first describe the grinding mechanism 7 as shown on a larger scale in Figs. 4i, 5 and 6. Referring' to those figures, there is there provide-d a suitable frame 13 having journal bearings l5 in which is mounted a grinding roll 1T of stone or other suitable material which may be directly driven by the pulley 19 shown in Fig. et. A similar opposed roll 2l, is utilized which is herein shown as mounted in journals 23 on a slide 15, 1921. Serial No. 445,204.

25 moving on undercut ways 2 on the side members of the frame 18. lhe mounting of the roll 2l in this manner provides for an adjustment which will hereafter be described.

ll suitable housing' or cover 29 may encase the. grinding couple consisting ot' the rolls l? and 2i, and a discharge spout 3l may bc provided for discharging the ground pulp which has passed between the rolls. A spray pipe beneath the rolls provides for washing the ground or refined pulp from their surfaces.

rlhe two rolls 17 and 2l rotate in opposite directions in Contact one with the other but at markedly different speeds. For example, the roll 17 may conveniently rotate about four hundred times for each rotation of the roll 2l. In the present instance, the shaft ofroll 17 which is directly driven by the pulley 19 is provided with a worm 35 (see Fig. Il) meshing with :i worm wheel Il? onv a shaft 39 carried by brackets on the side of the frame, and this shaft 39 carries a worm Lil meshing with a worm wheel 43 on the shaft of roll 2l. This transmission train provides for a great reduction in speed and also permits adjustment of the roll 2l as hereinafter described.

Preferably, l provide. for reciprorating one of the rolls axially during its rotation in Contact with the other roll and in Figs. Ll: and 6 l have shown a suitable mechanisn'i for applying this reciprocating motion to the roll 17. The roll i7 may slide axially in its bearings 15 and the shaft thereof has pivoted thereto a yoke l5 formed on one end of a level' 47, which is pivoted at i9 to a bracket projecting from the side of the frame. The other end of the lever may be formed as a fork 5l slidably receiving a block 53 in which works an eccentric on shaft 39. Thus on each revolution of the shaft 39 the roll i7 will be reciprocated axially, sliding in its bearings 15.

During the operation of a machine of this nature, the rolls gradually wear and I have herein provided for automatically compensating for this wear by slowly advuncing one roll toward the other. lt will be understood that the amount of this advance is very small, amounting to a slight fraction of an inch daily. As has alreadh been described, the roll 21 is mounted on a slide 25 so it can be moved toward `and from roll 17. To advance the roll 21 automatically toward the opposed fixed roll 17 theY slide 25 may be provided with a fixed nut 57 which receives the screw shaft 59 journalledV in the end of the frame 13 and provided with a thread of slow pitch. The screw shaft 59 carries a worm wheel 61 driven by worm 63 on a ratchet shaft 65. As best shown in Fig. 4, the shaft 65 carries at one side of the machine a fine toothed ratchet 67 adapted to be driven by a pawl 69 on the lever 71. The lever 71 is oscillatedby a wiper or cam 73 on the shaft of the slow moving roll 21. Thus for each revolution of the roll 21, which takes place comparatively infrequently, the shaft 65 is p Y turned a slight fraction of a revolution and by the worm and worm wheel 61-63 and the screw connection 59-57 `this movement is still further reduced to give an almost imperceptible movement of advance to the slide 25 just sui'iicient to compensate for the abrading wear on the stone roll 21.

Referring to Fig. 5, the pulp or like material which is to be ground is delivered through the passageway 11 to the bite of the rolls 17 and 21. A column of the material to be ground is delivered through the passageway 11, and this is supported and sustained by the slow moving roll 21 which provides an abutment surface and the end of the column is subjected between the points a and to a grinding and abrading action by the rapidly rotating roll 17. The material ground from the end of the column is then carried between the bite of the rolls at the point 0 and subjected to a final disA integrating action.

In installing the grinding mechanism 11, a feed is provided therefor whereby there may be constantly delivered to the grinding couple a column of pulp under a substantial pressure. By substantial pressure I mean to distinguish from some such slight pressure as might be exerted by a small amount of material in a shallow hopper and refer to pressure amounting to substantially twenty pounds per square inch or more, and provided by a columnar mass of material pressing with considerable force on the arc a-b of the roll 17, which acts against the same somewhat as it would against a solid body forcibly thrust thereagainst. This pressure may be provided for by carrying the. passage 11 to an adequate height to insure the desired pressure by gravity or, as herein, in a column of lesser height with the assistance of mechanical pressure-creating means which are of such nature as to `permit continuous operation of the mechanismV as long as there is a supply of pulp or like raw material. The passageway 11 is in any event preferably of considerable mae/ici height, say sixteen feet where such pressurecreating means as are here shown in Figs. 1 and 2 are utilized.

Referring to Fig. 1, the passageway 11 is herein fed ,from a hopper 75 by means adapted continuously to deliver material to the passageway 11, and also to exert a pressure on the column of material which fills the same. This is herein effected by a conveyor 77 in the form of an rrrchimedean screw at the bottom of the hopper. A stirrer comprising the curved vanes or arms 79, as best shown in Fig. 2, may operate in the bottom of the hopper to sweep the material toward the screw 77.

The screw 77 and stirrer 7 9 are carried by a shaft 81 driven by bevel gearing from a ulley 83 through the medium of a slip clutch 85, the parts of which are held in engagement by a spring 87. Adjustment of the spring S7 determines the pressure which the conveyor 77 will exert on the column of pulp in the passageway 11 and the clutch 85 will slip if this pressure is exceeded, thus momentarily stopping the conveyor and preventing injury to the parts.

To permit compensation from time to time for the shifting of the line of contact between the grinding couples 17 and 21 due to the wear which is compensated for by the movement of the roll 21, passageway 11 may be mounted as best shown at 89 in Figa to permit it to be shifted relatively to the parts of the grinding mechanism 7.

By the mechanism described the column of pulp in the passageway 11 is supported by the slow moving roll 21 and pressed with substantial pressure as already described against the arc a-b of the fast Vmoving abrading roll 17 which, however, makes Vcontact with the roll 21 and does not grind against any fixed parts of the mechanism. Thus, as the roll 17 tears away portions from the bottom of the column of pulp, they are passed through the bite of the roll which is maintained tight by the automatic compen sating advance of the roll 21 as already explained and there is no tendency to ri off slivers and deliver them from the mac ine without adequate comminution. This feature of obtaining a grinding action under pressure along the arc a-b with the immediate subsequent passage of the ground material through a grinding couple is an important characteristic of my invention as herein disclosed. i

Having described in detail the particular embodiment of my invention shown by way of example in the accompanying drawings, what I claim as new and desire to secure by Letters Patent I shall express in the following claims.

Claims:

1. A grinder as for pulp comprising a pair of rolls, means for rotating the same an ,means for automatically slowly approximating the rolls during operation to compensate for Wear.

2. A grinder as for pulp comprising a pair of rolls, one being mounted for movement toward and from the other, screw means for moving the same and means for actuating said means on rotation of the rolls.

3. A grinder as for pulp comprising a roll, a sliding frame carrying an opposed roll, low speed advancing means for said frame, a ratchet for actuating said means and a ratchet lever cam actuated from one of the rolls.

4. A grinder as for pulp comprising a pair of rolls geared together for rotation at high and low speeds respectively, one of said rolls being mounted for movement tovvard and from the other, low speed advancing means for said roll and actuating means therefor taking motion from the loiv speed roll.

5. A grinder as for pulp comprising a pair of rolls geared together for rotation at high and low speeds respectively, one of said rolls being mounted for movement toward and from the other, low speed advancing means for said roll including a screw, a ratchet for rotating the same, a ratchet lever and a cam driven by the low speed roll for moving the lever.

6. A grinder as for pulp comprising a grinding couple having horizontally opposed elements and means automatically actuated during the grinding action thereof for slowly approximating the elements to compensate for Wear.

7. A refiner for pulp or the like comprising a pair of differentially moving grinding rolls and feeding means comprising a passage delivering to the bite of the rolls and constructed to deliver continuously a column of pulp or the like exerting a forceful substantial, uniform pressure on the rolls.

8. A refiner for pulp or the like comprising a pair of differentially moving grinding rolls, a passage opening to the bite of the rolls and mechanical means for continuously delivering material to said passage and acting to exert through the column of material therein a substantial, uniform pressure on the rolls.

9. A refner for pulp or the like comprising a roll, an opposed abutment, and feeding means comprising a passage opening to the surface of the roll above the line of contact between the same and said abutment and constructed to deliveil continuously a column of pulp or the like exerting a forceful substantial, uniform pressure on the rolls.

l0. A reiiner for pulp or the like comprising a roll and an opposed abutment, a passage opening to the surface of the roll above said abutment, and mechanical means for continuously delivering material to said passage and act-ing through the column of inaterial therein a substantial, uniform pressure on said roll.

ll. A reiner for plup or the like comprising a roll and an opposed abutment, a passage opening to the surface of the roll above said abutment, and a screw conveyor operating in the upper part of the passage.

l2. A refiner for pulp or the like comprising a roll and an opposed abutment, a passage opcning to the surface of the roll above said abutment, mechanical feeding means for pressing pulp through said passage and means for driving said feeding means adapted to slip at a predetermined pressure.

ln testimony whereof, I have signed my name to this specification.

HERVEY G. CRAM. 

